1. Field of the Invention
The present invention relates to an information recording sheet, in particular to an information recording sheet on which a full-color image such as a face photograph can be fixed and formed and different kinds of information is rewritable.
2. Related Background Art
Recently, attentions in various card fields are focused on an information recording sheet on which a full-color image such as a face photograph can be formed and information is rewritable, that is, an information recording sheet having both regions for a fixed information recording layer and a variable information recording layer on a substrate sheet.
As one example of various variable information recording layers, a reversible heat sensitive recording layer is known which includes an electron donor color compound (coupler) and an electron acceptor compound (developer) as critical components. The reversible heat sensitive recording layer includes a function for generating a color recording condition by heating/melting and then cooling down quickly and a non-color condition where a record is lost by heating/melting and then cooling down slowly.
On the other hand, there are various methods for recording fixed information such as the electrophotograph method, ink-jet method, and thermal transfer method. Among those methods, the thermal transfer method is receiving attentions because of its advantages including easy operation and maintenance, smaller device and low cost, reasonable running costs, and less noise. Among various thermal transfer methods, the subliming thermal transfer method is known which uses a subliming dye as a color material and a thermal head for generating heat in accordance with a write signal in order to transfer the color material on a thermal transfer image receiving sheet. This recording method uses a dye as a color material so as to obtain a density gray scale. Thus, it can produce an extremely fine image and excellent color reproducibility in middle tone and gray scale reproducibility, which allow forming a comparable image in quality to a silver halide photograph.
As an information recording sheet including a variable information recording layer and a fixed information recording layer as above, Japanese Patent Laid-Open No. 155903/94 discloses an information recording medium. In the information recording medium in the Japanese Patent Laid-Open No. 155903/94, a reversible heat sensitive recording layer (variable information recording layer) and a transfer receptor layer (fixed information recording layer) are formed on a supporting body.
According to the subliming thermal transfer method, a fixed image is formed by placing a subliming dye acceptor layer of a thermal transfer image receiving sheet over a thermal transfer body (thermal transfer ribbon) having ink layers including a subliming dye layer of three colors (yellow, magenta and cyan), four colors (yellow, magenta, cyan and black) or five colors (yellow, magenta, cyan, black and over-laminate), and applying heat to the thermal transfer body by using a thermal head generating heat in accordance with a write signal so that the subliming dye in the ink layers sublimes and transfer on the dye receptor layer.
However, the information recording sheet in the publication has problems as follows: The publication discloses an information recording sheet forming a fixed information recording layer and a variable information recording layer on an identical surface of a substrate sheet. However, in the information recording sheet, the fixed information recording layer and the variable information recording layer are aligned in parallel on the identical surface of the substrate sheet. Therefore, when a card is manufactured, occupying areas of the fixed information recording layer and the variable information recording layer are determined in detail in advance. Here, special cares are required for forming each of the layers, which makes production of each layer difficult.
Further, it was difficult to eliminate a space between the fixed information recording layer and the variable information recording layer on an identical place in a recording card of a type that the fixed information recording layer and the variable information recording layer are aligned in parallel as in the conventional one. When a space is caused between each layer, the appearance of the information recording card is bad.
The present invention was made in order to overcome the problem. An object of the present invention is to provide an information recording sheet and a method of manufacturing the same, which looks good and allows easy manufacturing.
In order to achieve the object, the present invention is an information recording sheet including a substrate sheet, a variable information recording layer formed on the substrate sheet and a fixed information recording layer formed on a part of the variable information recording layer and made of a subliming dye receptor layer.
According to the information recording sheet of the present invention, a variable information recording layer is formed on a part or all of at least one surface of a substrate sheet without any care for its dimension and then a fixed information recording layer made of a subliming dye receptor layer is formed, which allows easier manufacturing. Further, an arrangement is adopted where a fixed information recording layer is stacked on the variable information recording layer. Therefore, a space is eliminated between each layer on a place of the information recording card, which makes it good looking.
Furthermore, in the information recording sheet of the present invention, the variable information recording layer is preferably a reversible heat sensitive recording layer.
Still further, in this case, information is preferably stored on the fixed information recording layer and the variable information recording layer, respectively; and thermal processing may be performed on a surface of the fixed information recording layer.
Information such as a letter or a figure is recorded on the reversible heat sensitive recording layer by heating it. However, the layer is turned to the coupler""s color during heating. If the information recording sheet remains in the coupler""s color, a user can not produce a desired color. Thus, as in the present invention, when thermal processing is performed on the surface of the information recording sheet, which receives a subliming dye and on which information is recorded, the coupler""s color can be removed thereby.
A method of manufacturing an information recording sheet according to the present invention includes the steps of forming a variable information recording layer on a substrate sheet and forming a fixed information recording layer made of a subliming dye receptor layer on a part of the variable information recording layer.
According to the method of manufacturing an information recording sheet of the present invention, a variable information recording layer is formed on a part or all of at least one surface of a substrate sheet without any care about its dimension and then a fixed information recording layer made of a subliming dye receptor layer is formed, which allows easier manufacturing. Further, an arrangement is adopted where a fixed information recording layer is stacked on the variable information recording layer. Therefore, a space is eliminated between each layer on a place of the information recording card, which makes it good looking.